Wind power plant voltage control optimization with embedded application of wind turbines and STATCOM

This paper proposes a method to find the optimal control scheme in the AC / DC converters considering the criteria of adjustment of voltage set points and the k-droop coefficient of each converter, with the objective of reduction losses in a HVDC grid. The differential evolution method is used for this optimization. To do this the control strategies and their characteristics is explained for each option of control system. The selection of the voltage control station (slack) is described together with the algorithm of selection of optimal voltage control scheme and the algorithm of optimization of voltage set points. Also, the CIGRE B4 DC grid test system benchmark is tested in steady and dynamic simulation to determine the advantages of the selected optimal control scheme and verify that the system maintains the stability when a fault has occurred.

Optimization of wind power generation to minimize operation costs in the daily scheduling of hydrothermal systems

As the wind power penetration increases, the frequency stability of the power system is deteriorating. Thus, it is expected that the wind power plants (WPPs) will be required to produce the inertial response during the short-term large-scale frequency disturbances. To study the effects of the inertial response of the WPP, the dynamic equivalent model (DEM) of the WPP should be able to emulate the inertial response of the actual WPP. Otherwise, the simulated system frequency would be different from the actual one. Therefore, the inertial response identification algorithm (IRIA) is proposed in this paper. The IRIA is able to identify the values of the droop gain and the inertia constants of the WPP according to the actual system frequency and the active power output of the actual WPP. The simulation results demonstrate that the DEM of the WPP and the actual WPP have similar responses of the active power output and the rotor speed under two frequency disturbances. In addition, the FNs of the simulated and actual system frequencies are very close. As a results, the effectiveness of the IRIA is successfully proved.

Wind power is still the most promising renewable energy source in the year of 2014. Wind power is considered feasible replacement of fossil fuels and energy production using this resource is increasing with the passage of time. Growing wind power production has impacts on the systems synchronized with these wind turbines. As the wind power penetration increases to the main power grids systems, the respective power system operators are more concerned about the reliability and stability of their systems. This increase of wind power penetration in system means that the wind turbines are replacing conventional power plants that usually control and stabilize the system. If this power penetration surpasses a certain level, control tasks for wind turbine system also needs to be considered. If the wind speed increases, much power is produced through turbines. The main problem we are facing in wind power production is that even after generating more than enough power to meet the load demands, surplus energy is being dissipated by dump load, otherwise it can create threat for power system stability as surplus power can have adverse effect on the frequency and voltages. In normal cases, surplus power is dissipated by using dump load. But enough portion of produced power is being wasted this way. In this study, an efficient controller for effectual wind turbine operation by controlling dump load is proposed to keep the system stable and the surplus dumped power is also consumed in productive way through heat generating system which increases the power system overall efficiency.

As the wind power penetration increases, the frequency stability of the power system is deteriorating. Thus, it is expected that the wind power plants (WPPs) will be required to produce the inertial response during the short-term large-scale frequency disturbances. To study the effects of the inertial response of the WPP, the dynamic equivalent model (DEM) of the WPP should be able to emulate the inertial response of the actual WPP. Otherwise, the simulated system frequency would be different from the actual one. Therefore, the inertial response identification algorithm (IRIA) is proposed in this article. The IRIA is able to identify the gain of the inertial controller and the inertia constants of the WPP according to the actual system frequency and the active power output of the actual WPP. In this article, the actual WPP is represented by the detailed model. In order to prove the effectiveness of the IRIA, three cases with different gains of the inertial controller are studied. The simulation results demonstrate that the proposed IRIA allows the DEM of the WPP to generate similar response of the active power and lead to close response of the system frequency as the actual WPP does in three different scenarios.

The integration of wind power in electricity generation introduces challenges on power quality issues. This paper proposes an algorithm to mitigate the harmonic distortion at the point of connection (PoC) of a wind power plant (WPP). Instead of opting to conventional method using passive filters to mitigate harmonics, this method only upgrades the control functions of the existing control systems of a WPP without additional investment. The mitigation algorithm performs the measurements at the PoC for a time window, which is transformed and analysed in frequency-domain. Then, it calculates the required harmonic current injections for selected wind turbine(s) to cancel the harmonics at PoC based on the frequency-dependent nodal analysis. To validate the algorithm, a generic WPP layout with multiple strings and field measurements of harmonic emission provided by Vestas Wind System A/S is used to simulate the harmonic propagation in the WPP using the MATLAB/Simulink along with PLECS Toolbox.

Optimizing the sizes of wind and photovoltaic power plants integrated into a hydropower station based on power output complementarity

According to the characteristics of double fed asynchronous generator rotor energy flow, research and design based on the DSP control with two-way flow of energy function of Dual PWM converter and discusses the grid side converter control method of Dual PWM converter in particular. The wind turbine simulation model is established by using the electromagnetic transient PSCAD/EMTDC software. The simulation system is used to simulate the P, Q decoupling control and maximum wind energy tracking control of the generator. Wind is a natural phenomenon generated by the solar radiation heat, the earth's surface caused by uneven heating of the atmosphere. It is estimated that only 1% of the wind on the ground will be able to meet the needs of the world's energy. With the continuous improvement of the level of wind power generation technology, the cost of wind power gradually reduced, considering environmental benefits, the cost will be close to the cost of coal-fired power generation. Therefore, great efforts to develop wind energy as the representative of the renewable energy and new energy, to achieve sustainable development, has become the consensus of the whole society, strategic choice to solve the energy crisis and environmental problems. 2.Overview of control technology of doubly fed wind power gener ation Wind power is the kinetic energy contained in the natural wind into electrical energy in the process, the wind turbine wind energy capture and convert it into mechanical energy, driven by rotary generator, and the generator for converting mechanical energy conversion into electrical energy. As countries around the world pay more attention to wind power, wind power has become the world's fastest, most widely studied and applied new energy technology. With the development of wind power technology, wind turbine, wind turbine generator, converter and its control system and the way of the wind turbine, there are different types of. Among them, the doubly fed wind power generation system due to the converter control capacity is small, the speed of operation range wide characteristics become currently the world's most widely used VSCF wind power generation system. Variable speed constant frequency generator in asynchronous generator rotor side applied three-phase low frequency current to realize AC excitation, the output power is constant frequency and constant voltage amplitude, frequency, phase of the exciting current control. At the same time, the active power and reactive power decoupling control of the generator is realized by using the vector control technology. Control active power capable of adjusting the rotation speed of the wind turbine, to capture the maximum wind power tracking control; regulation of reactive power adjustable power factor and improve the dynamic and static stability of the wind turbine and power system operation. In addition, the VSCF wind power generation technology, so to achieve good flexible connection between the generator and power grid system, compared with the traditional constant speed constant frequency generation system easier to achieve grid connected operation and operation

Advanced control of large-scale wind turbines: Structural load reduction and lifetime control

The use of energy storage systems (ESSs) has become a feasible solution to solve the wind power intermittency issue. However, the use of ESSs increases the system cost significantly. In this paper, an optimal power flow control scheme to minimize the ESS capacity is proposed by using the zero-phase delay low-pass filter which can eliminate the phase delay between the dispatch power and the wind power. In addition, the filter time constant is optimized at the beginning of each dispatching interval to ensure the fluctuation mitigation requirement imposed by the grid code with a minimal ESS capacity. And also, a short-term power dispatch control algorithm is developed suitable for the proposed power dispatch based on the zero-phase delay low-pass filter with the predetermined ESS capacity. In order to verify the effectiveness of the proposed power management approach, case studies are carried out by using a 3-MW wind turbine with real wind speed data measured on Jeju Island.

The integration of a Wind Power Plant (WPP) is a solution to increase the reliability of the electricity supply. Moreover, it potentially affects power system dynamic operation and control. The novel features of WPP involve fluctuated wind power injection, less-inertia characteristic, and sophisticated control system alter power flow of the power system and may interact with compensator devices and the existed synchronous generators. This paper investigates the effects of WPP integration on Sub-Synchronous Resonance (SSR) of the power system. A practical test system of South West Sulawesi is investigated. Three analytical methods; frequency scanning, modal analysis, and time-domain simulations, were proposed to analyze and assess the impact of DFIG based WPP integration on the SSR. It was monitored that the DFIG based WPP contributed to enhancing the system dynamic performance. The additional power injection from DFIG based WPP might relieve the stress of the synchronous generator and reduce the transmission line congestions. The more damped situation with WPP integration resulted in mitigation of the oscillatory conditions at sub-synchronous frequency.

During recent years, wind energy has moved from an emerging technology to a nearly competitive technology. This fact, coupled with an increasing global focus on environmental concern and a political desire of a certain level of diversification in the energy supply, ensures wind energy an important role in the future electricity market. For this challenge to be met in a cost-efficient way, a substantial part of new wind turbine installations is foreseen to be erected in big onshore or offshore wind farms. This fact makes the production, loading and reliability of turbines operating under such conditions of particular interest.

This study presents a technoeconomic analysis of a hybrid wind‐PV (photovoltaic) power plant (HPP) compared to onshore wind power plants (WPPs) and photovoltaic power plants (PVPPs) in the Nordic electricity market, focusing on locations in Finland and Sweden. Wind power capacity has recently increased significantly in the Nordics, increasing the profit cannibalization of wind power. Renewable energy subsidies have been phased out in Finland and Sweden, thus new wind and PV power value creation is formed from the power market. The PV power capacity has also encountered significant growth in the Nordics. However, the capacity is still relatively low, allowing more revenue for produced PV power compared to wind power. The lower PV power profit cannibalization has increased interest in HPPs instead of WPPs. This contribution studies the economic feasibility of wind and PV power in changing market conditions in the Nordic electricity market. The market operation is modeled with three different configurations including selling all the power into the day ahead spot market and baseload or pay‐as‐produced power purchase agreement (PPA). In addition, a battery energy storage system (BESS) investment is analyzed using the operating strategy of shifting production to more profitable spot price hours. This study shows that due to the profit cannibalization and high cost of capital, the power plants are currently not profitable in the Nordic electricity market except when the bidding area has high average spot prices. The worst profitability was with WPPs when exposed to the market shape risk and with PVPPs when pay‐as‐produced PPA was agreed upon due to the higher levelized cost of electricity. However, the PV power profit cannibalization is expected to increase in the future as more PVPPs operate in the Nordic power market. Thus, the PVPP shape risk may increase in the future as well.

As wind energy adoption is growing, ensuring the efficient operation and maintenance of wind turbines becomes essential for maximizing energy production and minimizing costs and downtime. Many AI applications in wind energy, such as in condition monitoring and power forecasting, may benefit from using operational data not only from individual wind turbines but from multiple turbines and multiple wind farms. Collaborative distributed AI which preserves data privacy holds a strong potential for these applications. Federated learning has emerged as a privacy-preserving distributed machine learning approach in this context. We explore federated learning in wind turbine condition monitoring, specifically for fault detection using normal behaviour models. We investigate various federated learning strategies, including collaboration across different wind farms and turbine models, as well as collaboration restricted to the same wind farm and turbine model. Our case study results indicate that federated learning across multiple wind turbines consistently outperforms models trained on a single turbine, especially when training data is scarce. Moreover, the amount of historical data necessary to train an effective model can be significantly reduced by employing a collaborative federated learning strategy. Finally, our findings show that extending the collaboration to multiple wind farms may result in inferior performance compared to restricting learning within a farm, specifically when faced with statistical heterogeneity and imbalanced datasets.

During recent years, the size of individual wind turbines has grown closer to 10 MW, and the size of wind power plants has increased significantly to 300 MW or more. This growing size of wind power generation requires that careful evaluation of transient stability of the overall grid should be undertaken. This paper attempts to investigate the impact of wind power plant penetration on the transient stability of the grid. Transient stability for different faults is investigated via simulation. A wind power plant with 22 turbines operated in variable speed mode will be used as the test subject of the study. As a comparison, we replace the test subject wind power plant with a conventional wind power plant (synchronous generator) and compare the results for the same faults.